Hillocks of Rosne
the hillocks of Rosne - or Rône - are located in the French Vexin, with the limit of the departments of the Val-d'Oise of the Oise. They consist of a Butte-témoin in the form of square of approximately 4 km the length, highest of the plate of the Vexin. With its 217 meters, the top of the solid mass is the culminating point of the area Île-de-France.
The hillocks are located on the territory of the communes of Haravilliers, Heaulme and Neuilly-in-Vexin in the department of the Val-d'Oise; Chavençon and Neuville-Bosc in the Department of Oise.